Coating machine for applying dry particulate material



July 8, 1952 PAAscHE 2,602,418,

COATING MACHINE FOR APPLYING DRY PARTICULATE MATERIAL 2 SHEETSSHEET 1 Filed May 21, 1949 i i a g 1 1 'Tx fig I HM &

E x 1 "%N% 4&3

. Q] 1 R "WELL-L i win-f 4- '(INVENTOR:

6M flpmce,

ATTORNEYS.

J. A. PAASCHE July 8, 1952 COATING MACHINE FOR APPLYING DRY PARTICULATE MATERIAL 2 SHEETS-SHEET 2 Filed May 21, 1949 INVENTOR. %em a. a

AiTTORNE Y5.

Patented July 8, 1 952 llNlTED STATES PATENT OFFICE.

COATING MACHINE FOR APBLYING naY PARTICULATE A'IEBIA Jens A. Paasche, Wilmette,.j1ll. Application May 21, 1949, Serial No. 94,673 8 Claims. (Cl. 118312) 1 The, present invention relates generally to amach e for coating ob ects-and mo e pa t eslarly for coating a moving sheet with powder, ron e or ot e om inuted dry c a in mater al- 1 common method of applying such coating m ri an bi -c i d re ne a ei ml carrying the coating material, fi'mfi .1 1 ace f the ect to b coate nher nt in h m tho 'o e ns a the, r bl m Of applying.

themoving sheet and to "facilitate the recovery oi the surplus material notadhering to the sheet; toprovide an improved arrangement-of two parallel, substantially-closed circuits of materialladenair streams from one of which circuitsthe desiredamountof material-laden air under pressurediverted-to the housing'for application of the material onto the sheet traveling through said housing and-to which. circuit is returned the surplusinaterial not adhering to the sheet, and theotherof which circuits filters air from the material-laden air streamsumcient to compensate-tor the air drawn into the housing during the-spraying'operation; to provide an improved arrangementof said housing affording the ad.- mission ofair into said air streams'sufficient to prevent the escape of material into the atmosphere surrounding said housing; to provide improved means for adding a measuredsupply of fresh coating material to the air stream; and to rovide a ma h ne Q t i .k which is n pe sive to manufacture, easy to install, and effective in in at n I t e cc m n ing vfimw s:

TflF e; 1 id evati n f n im oved cq 11, 8 iapparatus constructed in accordance with 1S inlientiq I 2 is anenlarged, fragmentary detailof the applicator, taken on the line 2-2-of Fig. 1';

" Fig. "'3 is a reduced plan view .of the machine, as shown in Fig. 1;' c Fig. 4 is an enlarged, tional detailtaken on the line qeetpf 'Fig. 3;

transverse, vertical, sec,-

Fig. 5 is a perspective view of the spreading.

nozzle which is'used withthe applicators;

Fig. 6 'i's an enlarged, longitudinal, sectional detail of the spreading nozzleshowninFig. 5; and f Fig. '7 is a transverse sectional detail of the same.

' The herein-shown preferred form of a coating machine, constructed inaccordance. with 7 this invention, comprises a material-applying housing It and a material-circulating mechanism ll co.-

7 acting to direct anair spray of dry'coating ma:

terialagainst asheet 12 as it is caused to traverse a vertical path through theshousing l0.

The housing l0 comprises a pair of outer walls It and two pairs of inner walls l5 and i5. These walls are arranged to forma pair of applicators or nozzles l1 and I8. and a pair of collecjing chutes l9 and 20. The. applicators and collectors are located on opposite sides of thepath of the moving-sheet l2 and above and below an applicating chamber. 2|. Dispersjng nozzles 22 are arranged at the upper ends. of the applicators l 'l and land collector tubes 2;3:are Q%t Q the lower ends of the collecting, chutes, l9- and 29. The nozzles or spreaders Z2 andcollecting tubes 23 are connected to the coatingrmaterial circw lating mechanism H, as, will be pointed ont rnore fully hereinafter.

The outer 'walls IA of the hopsing; 10 are of identical form. Each comprises an uppersec; tion 24, an intermediate section 25, and a lower section 2B, angularlydisposed with respect to each other. The opposed sections 24' and 2t, as will be most apparent from Fig. 1, are oi truncated triangular form with the respective bases 21 and 28 opposed and spaced apart by the respective rectangular shaped intermediate sec! tion 25. As will be most apparent from Fig. 61, the'outside, walls H ar arren es ha the pp ections 2.4 converse nwa dly towers t r b es-2:1, wherea the lower se ti ns 1 5 n toward the apexesawav fr m hebese T s; the applicat n hhmbfl1? s tren r se ros 86011101135 O tl UI- QQ WQ tr an ar o m w th he narrow, part alon the a e i s 1 andthc w er part al ae inch res 28' Q t e r s ee moans 3 form reinforcing peripherial flanges 29. By means of rivets 30 and spacing rings 3! the lower edges of the inner walls [5 are anchored in spaced relationship to the respective outer-Wall sections 24 (see Fig. 2). There is thus formed along the lower edges of the inner walls l5 a narrow slot 32 through which the coating material is discharged onto-the sheet I2 moving through the chamber 2!.

The lower inner walls It have their upper edges doubled back upon themselves to form reinforcing peripherial flanges 33 (see Fig. 4), which edges are closely spaced on oppositesides of the path of, the moving sheet [2. These inner walls converge toward the lower ends of the opposed lower wall sections 25 wherewith they form the collecting chutes I9 and 2G for the surplus coating material.

Wires 34 are arranged at intervals connecting the upper flanged edges of the lower inner walls with the intermediate wall sections 25. These wires serve not only to brace the inner walls I5, but also to properly guide the sheet l2 out of the chamber 2| into the path between the collecting chutes l9 and 20. v

The form of the nozzles 22 is most clearly shown in Figs. 5, 6, and 7. Each comprises a tubular part 35, theouter ends of which are closed, with which is associated a flanged inlet 35 and a fiat arcuateeshaped extension 37. The walls of the extension converge toward the median point of the arcanda slot 38 is formed in the periphery of the arcuate extension 31, through which the coating material is discharged into the applicators I1 and 18. As will be noted from Figs. 5 and 6, particularly, the slot 38 is larger at its inner ends than at its median point so as to insure a largerquantity of the material being dispersed toward the outwardly-flaring edges of the applicators l1 and I5. The inlet 351s arranged at right angles to the plane of the slot 38 so that material isdischarged against the opposite wall directly above the slot 38. This inconnection 47 which leads to the blower inlet.

' In thiscircuit, the powder, bronze flock, or other sures the bestpossible uniform dispersion of the 7 material through the slot 38. V

The nozzles 22 rest on and are suitably secured to flanges, with suitable intervening gaskets, formed at the truncated apexes of the respective innerwallsld and the outer-wall sections 24 of the applicators I! and I8.

The collector tubes 23 are likewise secured to axcuate-shaped flanges formed at the truncated apexesofthe inner walls l6 and the outer-wall sections 25.

The material-circulating mechanism I 1 comprises a blower 39,; the tandem material-circulating conduits 4i] and 3!, a material-delivering conduit 42, a separator 43, and a material-supply magazine or hopper 4 5. 'These combine to provide two closed parallel channels through which is simultaneously circulated material-laden air streams, from one of which circuits is diverted the required material-laden air to coat the sheet l2, and the otherof which circuitsprovides an escape of filtered 'ai r sufficient to compensate for the air drawn in through the housing ID during the coating operation.

The blower 39 is of the centrifugal type, set on a standard above the top of the housing It and is driven by a motor 6. The inlet and discharge of the blower are connected to the conduits 40 and ti by trunk connections 41 and 48.

The conduit lfil leads from the-trunk connection 48 with the blower discharge to the two collector tubes 23 for the housing I 0, which collector tubes,

comminuted material is filtered from the air stream, the air escaping through the separator outlet to compensate for the air drawn into the chamber 2| in the housing I0 between the inner ends of the inner walls 15 and [6.

The separator 43 comprises a casing 49 within which is suspended a fabric screen 50. At its lower end the casing outlet is funneled and connected to the trunk connection 4! leading to the inlet of the blower 39. r

The fabric screen 50 is attached at itslower end at the base of the casing 49 around the outlet and at its upper end is secured to a plate 5| embracing the conduit 4! and suspended from a motor-driven agitator 52.

The agitator 52 serves to keep the powder, bronze flock, or other comminuted material from accumulating on the fabric screen 50 and so clogging the pores or meshes as to prevent the escape of the air through the separator exhaust 56.

Butterfly damper valves 53, 54, and 55 are arranged in the conduits Miand 4i, and in the 'collector exhaust 56. r The adjustment of these dampers permits control of the flow of the material-ladenv air streams through the conduits: '41- and 42 and their connections, and, consequently, determine the characterof the material-ladenlair stream which is directed through the conduit 42 for the application of the material to the sheet 12 as it moves through the housing It. i

The material supply magazine or hopper 44 is a vertically-disposed cylinder witha funnelshaped bottom 55 connected by a short nipple 56 to feed fresh material into the conduit 40, intermediate the collector tubes 23 and the trunk connection 41 with the inlet of the blower 39. l A feed auger 51 in the nipple 56 and a wire agitator 58 in the magazine are operated bya motor 59 to deliver measured amounts of they powder, bronze floclgor other comminuted material ;to

- the air stream circulating through the conduit 30 on its way to the blower 39. Theherein-shown motor 59 is air-driven and its connection to a suitable source of compressed air is through an air conditioner 60 designed to remove moisture, oil, or other impurities in the air and thereby insure the efiective operation of the motor .59.."

A door 61 in the magazine 43 permits fresh supplies of dry coating'material to be added to the magazine or hopper as needed. 1 3

In operation the sheet [2 which is'tobe coated is moved downwardly between the wallsiliiand l 6 of the housing Ill, traveling over suitablerollers such as shown at 62 and 63 of 4. An, air stream laden with powder,bronze fio'ckgor' other comminuted material is discharged through the slots 32 of the applicators I and [8 on that poi tion of the sheet 12 which is ;within the spraying chamber 21. By reason ofthe form ofithe nozzles 31 and their position .within' the applicators l t. H: and 18 the coating spread across thelfullwidth of the sheet" I2 The air stream of material circulatingthrough the conduit 40 sets up a suction. in the collector chutes l9 and Obviously, this causes airl toof air will be drawn-in between thesheet l2 andthealowerends of the inner: wallsl=5 ofitheapplicators II and 18. As a'consequenceofi-this snction and the inflowingair, any surplus' mate rial not adhering to the sheet 42 is drawn down through v the collector chutesl9 and-.10" into the tubes 23, thereby being returned-to and becoming apartof the airstream circulating through the conduit 40' with itstrunk-connections '41' and 481- and the. blower 39'.

The material 11 the air stream: produced by the blower 39 discharged through-the trunk connection- 48 divides, and part of it flowsthrough the-conduit 4i and hence throughthe separator 43-; In theseparator, sufficient air to com'p'ensate for that drawninto the spraying chamber 21, as hereinbefore explained, is filteredout throughthe screen 50 and escapes through the separator exhaust 56.

The setting of the valves 53, 54,. and 55 determines the portions of. the material-laden: air. stream, emerging fromthe blower 39 through the trunk connection 4 8 which will pass through the respective conduits 40 and 41- and the portion thereof which will be diverted from the, blower 39 into the conduit 42 to be delivered to the applicators l1 and it.

Although but one specific embodiment of this invention has been herein shown and described,

it'wi'llbeunderstood that details of the construction; shown'may be altered without departing from the spirit of the invention as definedbythe follhwing claims. '--];'.claim:

1'. In a machine for applying small particles of dry coating material simultaneously to the opposite faces of a traveling sheet, the combination of a housing comprising a pair of oppositely disposed, vertically extending outer walls and pairs of upper and lower inner walls arranged on opposite sides of the path oi -travel of the sheet, each of said outer walls being formed of three angularly-disposed sections including upper and lower sections of truncated triangular form and an intermediate section of generally rectangular form, said upper and lower sections being inclined inwardly relative to the respective intermediate sections and with their bases 0pposed and vertically spaced apart by said rectangular intermediate sections, said pairs of upper and lower inner walls being substantially coextensive with the respective upper and lower outer-wall sections, said upper inner walls being arranged with their bases slightly converging toward the adjacent outer-wall sections so as to provide applicators having narrow openings along the adjacent lateral edges of the respective intermediate wall sections through which material is directed onto the sheet, said lower inner-wall sections having their base edges closely spaced on opposite sides of said path with their truncated apexes converging toward the apex ends of said outer-wall sections, a material-spreading nozzle located between the truncated apexes of each of the upper outer-wall sections and their corresponding inner walls, a collector tube lomaterial is uniformlycate'd at: the truncated. apexes or each: oi said lower I outer-Wallisections and? their correspond ing inner walls, and a blower havingits-inlet:

connected-to said collector tubes and an outlet connected tosaid nozzles so as to cause a con-- tinuous circulation of materialthrough saidhousing.

2.'- In a machine for applying small particles-- of dry coating material simultaneously tame-op 'positefaces of atraveling sheet, the combina-= tion ore-housing comprising a pair-ofoppositely disposed, verticallyextending outer walls and; pairs of 'upper' and lower inner walls arranged onopposite" side's-or thepath of travel: of the sheet, Y eachof said outer wallsincluding an} uniper section, an intermediate section, and a lower.

section, saidpairs of upper and lower inner' walls being substantially coextensivewith the -respec tive' upper and lower outer-wall. sections, saidthrough which material is directedonto the sheet of travel of thesheet, said along the direction lower inner wall sectionshaving their baseedges connected to thebase edges; of: sa=id.-lowe'r sco tions of said" outer walls and havingtheir: t'op edges located closely adjacent the sheet provirhing'jan opening for the sheet to" leave the nia' chine; a material spreading" nozzlelocatedbe tweenl each of" the upper outer-wall: sections" and inner walls, a collector tubelocated at the bottom cream of said lower outerwall sections andtheir'corresponding inneriwalls ablower havingits inlet connected to said col lector tubes and an outlet connected to said noztheir corresponding;-

.zles so as to cause a continuous: circulation-of material through said housing; and means COl-l' nected to a blower outlet and adapted to separate the material notpdel'ivered tosaid nozzles and return such separated'material to said blower inlet. I

3. A coating machine for applying small particles of dry coating material to a verticallytraveling sheet comprising a pair of spaced, coextensive vertically-disposed walls of substantially triangular form, said walls being spaced apart at their apexes and converging therefrom toward each other to form a narrow openin along the bases of said walls adjacent said path and through which material is discharged against said sheet, and an arcuate-shaped nozzle located intermediate said walls in the region of their apexes, said nozzle having a pair of arcuate shaped side walls which define an opening having a gradually increasing width from its center towards the opposite ends of the opening.

4. A coating machine for applying small particles of dry coating material to a verticallytraveling sheet comprising a pair of spaced, coextensive vertically-disposed walls of substantially triangular form, said walls being spaced apart at their apexes and converging therefrom toward each other to form a narrow opening .along the bases of said walls adjacent said path liver material to said nozzle inv a direction substantially perpendicular to the general plane of. said nozzle.

5. A machine for applying particles of dry coating material to an object comprising, a housing defining a, chamberfor the reception of said object during the application of the material;

rial in said housing to said blower inlet, and a' separator interposed in the other said branch conduit and adapted to screen the material from the air stream for redelivery to said blower inlet,

6. In a system for applying small particles of dry coating material to an object, the combinationof means defining a chamber for receiving the, objectto be coated and into which chamber saidcoating material-is delivered in an air stream o to be impinged upon the surface of said object, conduit means defining a pair of parallel closed all circuits, a blower having its inlet and discharge connected to both of said circuits to effect a simultaneous and continuous flow of air through said circuits, means for introducing a measured amount of dry coating material into one of said circuits, means for diverting from one of said circuits a material-laden air stream for delivery to said housing chamber, one of said circuits being connected to said chamber to withdraw the surplus of material not adhering to said object and returning said material to said one circuit, and a separator interposed in the other said circuit and adapted to permit an escape of filtered air commensurate with the air that is drawn-into said housing chamber,

7 A coating machine for applying smallparticles of dry coating material simultaneously to the opposite faces of a travelling sheet, comprls'=, ing a pair of vertically disposed-applicators and opposed collectors defining a vertical path for the sheet, an applicating chamber located inter-V mediatesaid applicators and saidcollectors, said chamber having an inlet opening therein for re-;,

ceiving the sheet, said applicatorsbeing located atand directed away from said opening along the line of travel of the sheet, a material maga zine, means for delivering material from said magazineto said applicators, said collectors-beingv disposed below said chamber and being adapted to collect the surplus coating material that does not adhere to the sheet, and means 'for deliver-- ing'to said applicators the surplus material drawn from said collectors;

8. A coating machine for applying small particles of dry coating material to a vertically disposed traveling sheet comprising a'pair'o-f spaced, vertically-extending walls, said walls being spaced apart at theirupper ends and converging therefrom toward. each other to form a narrow opening at their lower ends, said opening being adjacent the path of travel of the sheet, and an'arcuate shaped nozzle located intermediate said walls in therregion of their upper ends,

said nozzle having a pair of arcuate shaped side walls which define an opening having a gradually increasing width from its center towards the opposite ends of the opening.

- JENS A. PAASCHE.---

' REFERENCES CITED The following references are of record in the file of this patent: V I, UNITED STATES PATENTS a Number Name Date 1,876,251 Lehman Sept. 6,1932 1,930,814 Lipsius Oct. 17, 1933 2,130,739 Honig Sept. ,20, 1938 2,173,032 Wintermute Sept. 12, 1939 2,338,499 Faris et al. Jan. 4,19% 2,419,835 Hester 1 Apr. 29, 1947 

